1. Field of the Invention
The present invention relates to an image recording apparatus and a recording defect inspection method for same, and more particularly, to technology for detecting defective recording elements by reading recorded test patterns.
2. Description of the Related Art
An inkjet recording apparatus is known which records an image by ejecting ink onto a recording medium using a recording head in which a plurality of nozzles that eject ink are arranged. In an inkjet recording apparatus, ejection failure caused by nozzle blockages may occur, as may nozzles having recording defects, such as landing deviations, caused by partial closing off of the nozzles. If a nozzle having an ejection failure or a nozzle having landing deviation arises, then a white stripe occurs in the output image.
On the other hand, technology is also known according to which test patterns for measuring recording characteristics of a recording head are output, and ejection failure nozzles and nozzles having landing deviation are detected on the basis of the results of measuring the density of these test patterns. In this way, by previously detecting ejection failure nozzles and nozzles having landing deviation, image correction using normally functioning nozzles becomes possible.
However, the work of inspecting ejection defects and landing deviations generally requires a long inspection time. In cases where an ejection defect or landing deviation has occurred in the test patterns that are the object of inspection, if the test patterns are inspected in sequence starting from an inspection object range corresponding to a recording head which has a low defect occurrence frequency, inspection also needs to be carried out in respect of test patterns in which no defects have occurred and therefore it takes time to determine the location of defects. If detection takes a long time, then countermeasures for dealing with the defective locations are delayed.
In view of problems of this kind, Japanese Patent Application Publication No. 2011-51225 discloses technology for evaluating respective recording defect occurrence forecasts for a plurality of recording heads, and analyzing test patterns in sequence starting from a head having the highest defect occurrence forecast. According to this technology, it is possible to shorten the time taken to detect ejection failure nozzles or nozzles having landing deviation.